1. Field of the Invention
This invention relates to a seat for a motor vehicle or the like and more particularly to a device which is disposed in the backrest which varies the contour of the backrest to unify the pressure applied to the seated occupants dorsal and lumbar regions.
As is well known a comfortable seat especially in a motor vehicle or the like contributes greatly to the seated occupants sense of well being and minimizes distraction due to irritation resulting from excess pressure being applied to a localized area of his or her body.
2. Description of the Prior Art
In an effort to provide the optimal seating comfort of a seated occupant, seats, especially those of motor vehicles and the like have been contoured. However there are a variety of statures and physiques and a contour perfectly suited to a tall thin person is highly likely to be rather uncomfortable to a short stout person.
Hence previous efforts to select a contour suited to all physiques has met with only partial success and thus there still remains a need to provide a seat, the contour of which can be varied to unify the pressure applied to, in particular, the dorsal and lumbar regions of person seated therein.
One attempt to solve the problem incorporates a tilting device which permits varying of the angle of the backrest with respect to the portion of the seat designed to support the gluteus maximus. However the contour of the backrest portion remains unchanged by this tilting and although aleviating the irritation somewhat, requires rather troublesome and time consuming trial and error setting of the angle; and a comfortable position when found is often ergonomically poor with respect, for example, of driving a motor vehicle, the person usually finding him or herself too far from the vehicle controls.